GB1341490A - Electrostatic extraction apparatus - Google Patents

Abstract

1341490 Electrostatic separation ONO CEMENT CO Ltd and S MASUDA 22 Sept 1971 [28 Nov 1970] 44122/71 Heading B2J An electrostatic precipitator having a gas inlet 26 and a gas outlet 34 comprises collecting electrodes 5, e.g. tensioned plates of stainless steel, arranged in three stages 2, 3, 4. Water containing material to absorb gaseous contaminants such as SO 2 , SO 3 , H 2 S and NO 2 is supplied from a tank 19 to nozzles 7 and is sprayed onto the electrodes 5 in stage 4, the tank being supplied with water and said material by pipes 20 and 21 respectively. Dust dislodged from the electrodes 5 in stages 2 and 3 by rapping mechanisms 29, 20 falls into hoppers 31, 32 for removal by a conveyor 33, whilst the slurry produced in stage 4 is collected in a tank 10, from which it is fed by way of a pipe 13 and nozzles 16 to the interior of a drying tower 15 provided at the gas inlet 26 so that the slurry is dried by the contaminated hot gases before these pass into the housing 1 of the precipitator. Contaminant-gas absorbing material may be added to the slurry by way of a pipe 17. Thus gaseous contaminants in the gas to be purified are removed partly in the tower 15 and partly in stage 4, whilst the particulate contaminants are removed in stages 2, 3 and 4, the purified gas being finally discharged to the atmosphere, after reheating if necessary, by way of the outlet 34 and a stack 35. A centrifugal separator 11 in the pipe 13 concentrates the slurry, separated water being returned to the tank 10. Preliminary dust extraction may be effected by a mechanical separator, e.g. a cyclone. A modified drying arrangement for the slurry is described with reference to Fig. 2 (not shown).